textproduct: Quad Cities

KEY MESSAGES

- Heat and humidity returns for the weekend and into next week. Heat indices may approach or exceed 100 Sunday into Monday.

- Outside of low chances for rain Friday morning, mainly dry conditions should be seen. Possible exceptions are where the ring of fire develops once the heat dome builds into the area.

SHORT TERM /THROUGH TONIGHT/

Issued at 148 AM CDT Thu Jul 23 2026

Continued cooler than normal with low humidity through sunset.

The question late tonight are the rain chances. Progged soundings show a considerable amount of dry air in the low levels; which makes sense given dew points in the 50s during the day.

Thus it appears that most of the forcing will go into cloud development late tonight. While some models develop precipitation, more are dry or mainly dry. Interestingly, the RRFS 18z and 00z runs were dry as was the 18z REFS.

The better rain chances are south of the IA/MO border but will go with some 20-40% rain chances generally south of an Ottumwa, IA to Galesburg, IL line. As we get closer to the event, the rain chances will probably lower and get pushed further south. Sprinkles are definitely in play given the deep layer of moisture above 700 mb.

LONG TERM /FRIDAY THROUGH WEDNESDAY/

Issued at 148 AM CDT Thu Jul 23 2026

Friday/Friday night Assessment...low (<20%) confidence on rain

Progged soundings of the atmosphere continue to show dry air in the low levels through Friday morning. Thus rain is questionable but with moisture in the mid-levels, sprinkles are on the table.

Like late Thursday night the rain chances generally look to be south of an Ottumwa, IA to Galesburg, IL line. Thus will keep 20-40% chances going for that area with slightly higher chances south of the IA/MO border.

Friday night the models show rain chances on the warm advection associated with the expanding heat dome. Again, the rain chances are not high; 20-40 percent south of an Ottumwa, IA to Galesburg, IL line with most of the area remaining dry.

Saturday through Sunday Assessment...very high (>95%) confidence of heat and humidity returning

The southerly flow that develops Friday night will continue through the weekend allowing heat and humidity to return. While the humidity will be noticeable Saturday, Sunday will be downright uncomfortable with dew points generally 70 to 75. Heat indices on Sunday look to approach 100 and may exceed 100 in some areas.

Sunday night through Tuesday Assessment...high (>80%) confidence on heat and humidity continuing

The heat and humidity will continue into the first part of the work week. Heat indices may again approach or exceed 100 on Monday which raising the question of potential heat headlines Sunday through Monday evening.

The wild card is where the ring of fire sets up. Organized storm complexes should move across Minnesota in Wisconsin before turning south and potentially moving into northern Illinois. The various models suggest the far northeast and eastern area could get side- swiped by a storm complex late Sunday night into Monday morning and again late Monday night into Tuesday. If this scenario does occur, it could affect any heat headlines for Monday.

The key will be where do the storm complexes Saturday night into Sunday develop and go. This will impact where the storm complex Sunday night into Monday forms and goes and likewise the Monday night into Tuesday complex.

Tuesday night/Wednesday Assessment...a certainty (>95%) of continued warm and humid conditions

By Tuesday night the tropical connection with the Gulf weakens which will allow dew points to generally drop back into the 65 to 70 range; humid but not oppressive. The heat dome ridge partially de- amplifies and turns the mid-level flow more west to east across the Midwest. As a result, the organized storm complexes should remain across Minnesota and Wisconsin.

AVIATION /12Z TAFS THROUGH 12Z FRIDAY/

Issued at 600 AM CDT Thu Jul 23 2026

High pressure maintaining acrs the mid and upper MS RVR Valley will make for another day of light sfc winds and mainly VFR conditions. There will be patches of 5-7K FT AGL stratocu, as well as some diurnal development of ambient CU of SCT-BKN coverage by afternoon, but again at VFR levels. Sfc winds today, when not light and variable, will be from the south to southeast at 5-10 KTs. Light and variable sfc winds return tonight after sunset.

DVN WATCHES/WARNINGS/ADVISORIES

IA...None. IL...None. MO...None.